A study of corrosion protection on copper by new polymeric agents: silane-modified imidazoles

Abstract

A new polymeric anticorrosion agent, which maintains efficiency at elevated temperatures or under high humidity environments, has been synthesized and its structure during use has been studied. Modified polyvinylimidazole(1), PVI(1), and polyallylimidazole(1), PAI(1) have been synthesized by free radical polymerization of N-vinylimidazole and γ-methacryloxypropyl-trimethoxysilane(γ-MPS) with azobis(isobutyronitrile). Thermal degradation of modified PVI(1) and PAI(1) has been studied by Fourier transform infrared reflection-absorption spectroscopy (FTIR-RAS). At 210°C, the polymer experiences degradation but does not form nitrile groups. Compared to the PVI(1) homopolymer, thermal degradation of modified PVI(1) copolymer shows different behavior possibly due to the different degradation processes. At elevated temperatures, modified PVI(1) suppresses the oxidation of the copper surface but the spectrum of modified PAI(1) shows the cuprous oxide peaks at 650 cm −1 and 611 cm −1. Under humid environments, both copolymers act as excellent anti-oxidants on the copper surface in the temperature range from 25° to 80°C. The effect of different mole ratio of the comonomers on corrosion inhibition has been studied in the 100% relative humidity condition. In spite of changing the mole ratio of the copolymers, the spectra of both modified copolymers under humid conditions was not accompanied by any of cuprous oxide at the temperatures studied.